An external defibrillator can receive wirelessly a data signal transmitted by a transmitting device over a communication link. The defibrillator can include a processor configured to monitor a reception parameter of the communication link while the data signal is being received and to set an alert flag if the processor determines from the reception parameter that reception of the data signal may be discontinued prematurely. The defibrillator can also include a user interface capable of outputting an alerting user notification responsive to the alert flag being set.
